/* Runde 7 ergänzt die vorhandenen Glasflächen und lässt R4/R5 unverändert. */
.theme-toggle {
  order: 3; flex: 0 0 44px; width: 44px; height: 44px; padding: 10px;
  display: inline-flex; align-items: center; justify-content: center; border-radius: 50%;
  color: var(--farbe-text); background: var(--glass); border: 1px solid var(--glass-edge);
  box-shadow: var(--glass-inner), var(--schatten);
  -webkit-backdrop-filter: blur(20px) saturate(160%); backdrop-filter: blur(20px) saturate(160%);
}
.theme-toggle[hidden], .topics-toggle[hidden], .book-search[hidden],
.book-category[hidden], .book-item[hidden] { display: none !important; }
.theme-toggle .theme-moon, .theme-toggle[aria-pressed="true"] .theme-sun { display: none; }
.theme-toggle[aria-pressed="true"] .theme-moon { display: block; }
.books-nav { position: relative; display: flex; align-items: center; flex-wrap: wrap; }
.topics-toggle { display: inline-flex; align-items: center; justify-content: center; flex: 0 0 44px; min-height: 44px; padding: 8px; background: transparent; color: var(--farbe-text); border: 1px solid var(--soft-edge); }
.topics-toggle[aria-expanded="true"] svg { transform: rotate(180deg); }
.topics-menu { width: 100%; display: flex; flex-direction: column; padding: 12px; gap: 2px; }
.topics-menu a { line-height: 1.35; }
.topics-menu .theme-control { margin: 10px 12px 0; }
.books-nav .topics-menu {
  position: absolute; top: 100%; right: 0; width: min(390px, 85vw);
  max-height: min(650px, 75dvh); overflow-y: auto; z-index: 51;
  border-radius: 22px; border: 1px solid var(--glass-edge); background: var(--glass-solid);
  box-shadow: var(--glass-inner), var(--schatten);
}
.books-nav[data-ready="true"] .topics-toggle[aria-expanded="false"] + .topics-menu { display: none; }
.topic-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 20px; }
.topic-tile { display: flex; flex-direction: column; overflow: hidden; border-radius: 24px; border: 1px solid var(--soft-edge); background: var(--farbe-karte); color: var(--farbe-text); box-shadow: var(--schatten); }
.topic-tile > .scene-picture { position: relative; z-index: auto; flex-shrink: 0; display: block; width: 100%; height: auto; aspect-ratio: 2 / 1; }
.topic-tile > .scene-picture img { position: static; display: block; width: 100%; height: 100%; object-fit: cover; }
.topic-tile > span { display: grid; gap: 8px; padding: 20px; }
.topic-tile strong { font-family: var(--schrift-serif); font-size: 1.25rem; line-height: 1.3; }
.topic-tile small { color: var(--farbe-text-mild); }
.library-tools {
  position: sticky; top: var(--library-top, 110px); z-index: 30; width: calc(100% - 40px); max-width: 1120px;
  margin: 0 auto 32px; padding: 12px 16px; border: 1px solid var(--glass-edge); border-radius: 24px;
  background: var(--glass); box-shadow: var(--glass-inner), var(--schatten);
  -webkit-backdrop-filter: blur(20px) saturate(160%); backdrop-filter: blur(20px) saturate(160%);
}
.topic-chips { display: flex; gap: 8px; overflow-x: auto; padding: 4px; scrollbar-width: thin; }
.topic-chips a, .topic-chip {
  display: inline-flex; align-items: center; min-height: 44px; padding: 8px 16px;
  flex-shrink: 0; border: 1px solid var(--soft-edge); border-radius: 999px;
  background: var(--farbe-karte); color: var(--farbe-text); font-size: .85rem; line-height: 1.4;
}
.topic-chip { margin-bottom: 18px; max-width: 100%; }
.topic-chips a[aria-current="true"] { background: var(--farbe-text); color: var(--farbe-hintergrund); border-color: var(--farbe-text); }
.book-search { display: flex; align-items: center; flex-wrap: wrap; gap: 8px 12px; margin-top: 10px; }
.book-search label { font-size: .85rem; }
.book-search input { min-width: 0; width: min(100%,320px); min-height: 44px; padding: 8px 14px; border: 1px solid var(--soft-edge); background: var(--farbe-karte); color: var(--farbe-text); font: inherit; }
#suchstatus { font-size: .85rem; }
.book-category { scroll-margin-top: calc(var(--library-top,110px) + 150px); }
.book-list.cover-grid { grid-template-columns: repeat(auto-fill,minmax(min(190px,100%),1fr)); gap: 24px; }
.cover-grid .book-item { flex-direction: column; align-items: stretch; gap: 16px; min-width: 0; padding: 20px; }
.cover-grid .cover-link { display: block; width: 100%; flex: none; }
.cover-grid .cover-art.book-cover { width: 100%; height: auto; aspect-ratio: 2 / 3; padding: 14% 10%; gap: 12%; }
.cover-grid .book-cover .cover-title { font-size: clamp(.85rem,1.4vw,1.1rem); line-height: 1.25; }
.cover-grid .book-cover .cover-author { font-size: .7rem; }
.more-topics { padding-top: 12px; }
.more-topics .topic-chips { flex-wrap: wrap; overflow: visible; }
.more-topics .topic-chips a { flex-shrink: 1; }
@media (max-width: 900px) and (min-width: 641px) {
  .site-header .brand-text { max-width: 120px; font-size: .85rem; }
  .site-header .container { gap: 8px; padding-inline: 12px; }
  .header-panel { flex: 1; }
  .header-panel nav.main-nav { width: auto; justify-content: flex-end; }
}
@media (max-width: 640px) {
  .site-header .theme-toggle { order: 2; }
  .site-header .header-donate { order: 3; }
  .site-header .header-panel { order: 4; }
  .books-nav { width: 100%; }
  .books-nav > a { width: 100%; }
  .books-nav .topics-toggle { display: none; }
  .books-nav .topics-menu,
  .books-nav[data-ready="true"] .topics-toggle[aria-expanded="false"] + .topics-menu {
    display: flex; position: static; width: 100%; max-height: none; overflow: visible;
    padding: 4px 0 4px 12px; border: 0; border-left: 1px solid var(--soft-edge);
    border-radius: 0; background: transparent; box-shadow: none;
  }
  .topic-grid { grid-template-columns: repeat(2,minmax(0,1fr)); gap: 12px; }
  .topic-tile > span { padding: 14px; }
  .topic-tile strong { font-size: 1rem; }
  .library-tools { width: calc(100% - 24px); padding: 8px 10px; }
  .book-search label { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .book-search { gap: 6px; }
  .book-search input { flex: 1; width: 120px; }
  .book-list.cover-grid { grid-template-columns: repeat(2,minmax(0,1fr)); gap: 12px; }
  .cover-grid .book-item { padding: 12px; }
  .cover-grid .book-item a.book-title { font-size: .9rem; overflow-wrap: anywhere; }
  .cover-grid .book-cover .cover-title { font-size: .8rem; }
  .cover-grid .book-cover .cover-author { font-size: .6rem; }
}
@media (max-width: 350px) {
  .topic-grid, .book-list.cover-grid { grid-template-columns: minmax(0,1fr); }
}
@media (max-height: 500px) {
  .library-tools { position: static; }
}
@supports not ((backdrop-filter: blur(20px)) or (-webkit-backdrop-filter: blur(20px))) {
  .theme-toggle, .library-tools { background: var(--glass-solid); }
}

@media (min-width: 641px) {
  .books-nav:not([data-ready]):not(:hover):not(:focus-within) .topics-menu { display: none; }
}